Este tema describe cómo cargar archivos (objetos) en un bucket con control de versiones habilitado.
Notas
En este tema se utiliza el endpoint público de la región China (Hangzhou). Si necesita acceder a OSS desde otros servicios de Alibaba Cloud ubicados en la misma región que OSS, utilice un endpoint interno. Para obtener más información sobre las regiones y los endpoints de OSS, consulte Regions and endpoints.
Este tema muestra cómo crear una instancia de OSSClient con un endpoint de OSS. Para conocer configuraciones alternativas, como usar un dominio personalizado o autenticarse con credenciales de Security Token Service (STS), consulte Create an OssClient instance.
Para cargar un objeto, debe contar con el permiso
oss:PutObject. Para obtener más información, consulte Grant a custom policy.
Carga simple
Si inicia una solicitud para cargar un objeto en un bucket con control de versiones habilitado, OSS genera un identificador de versión único para el objeto cargado e incluye dicho identificador en la respuesta como valor del encabezado x-oss-version-id. Si carga un objeto en un bucket con el control de versiones suspendido, OSS genera un identificador de versión null para ese objeto. Cuando el objeto que carga tiene el mismo nombre que uno ya existente, el nuevo reemplaza al anterior. De esta manera, cada objeto conserva únicamente una versión cuyo identificador es null.
A continuación se muestra cómo ejecutar una carga simple:
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize the OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name. Example: examplebucket. */
std::string BucketName = "examplebucket";
/* Specify the full path of the Object. The full path cannot contain the bucket name. Example: exampledir/exampleobject.txt. */
std::string ObjectName = "exampledir/exampleobject.txt";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
std::shared_ptr<std::iostream> content = std::make_shared<std::stringstream>();
*content << "test cpp sdk";
PutObjectRequest request(BucketName, ObjectName, content);
/* Upload the file. */
auto outcome = client.PutObject(request);
if (outcome.isSuccess()) {
std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
}
else {
/* Handle exceptions. */
std::cout << "PutObject fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Carga por anexión
En un bucket con control de versiones habilitado, la operación AppendObject solo se puede ejecutar sobre la versión actual de un objeto anexable.
Cuando ejecuta la operación AppendObject sobre la versión actual de un objeto anexable, OSS no genera una versión anterior para dicho objeto.
Si ejecuta la operación PutObject o DeleteObject sobre un objeto cuya versión actual es anexable, OSS almacena ese objeto como versión anterior e impide que se le sigan anexando datos.
No es posible ejecutar la operación AppendObject sobre un objeto cuya versión actual no sea anexable, como un objeto normal o un marcador de eliminación.
A continuación se muestra cómo ejecutar una carga por anexión:
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize the OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name. Example: examplebucket. */
std::string BucketName = "examplebucket";
/* Specify the full path of the Object. The full path cannot contain the bucket name. Example: exampledir/exampleobject.txt. */
std::string ObjectName = "exampledir/exampleobject.txt";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
auto meta = ObjectMetaData();
meta.setContentType("text/plain");
/* The position for the first append is 0. The return value indicates the position for the next append. Subsequent appends start from the end of the file. */
std::shared_ptr<std::iostream> content1 = std::make_shared<std::stringstream>();
*content1 <<"Thank you for using Alibaba Cloud Object Storage Service!";
AppendObjectRequest request(BucketName, ObjectName, content1, meta);
request.setPosition(0L);
/* Append data to the file for the first time. */
auto result = client.AppendObject(request);
/* View the version ID of the object after the append operation. */
if (result.isSuccess()) {
std::cout << "versionid:" << result.result().VersionId() << std::endl;
}
else {
/* Handle exceptions. */
std::cout << "AppendObject fail" <<
",code:" << result.error().Code() <<
",message:" << result.error().Message() <<
",requestId:" << result.error().RequestId() << std::endl;
return -1;
}
std::shared_ptr<std::iostream> content2 = std::make_shared<std::stringstream>();
*content2 <<"Thank you for using Alibaba Cloud Object Storage Service!";
auto position = result.result().Length();
AppendObjectRequest appendObjectRequest(BucketName, ObjectName, content2);
appendObjectRequest.setPosition(position);
/* Append data to the file for the second time. */
auto outcome = client.AppendObject(appendObjectRequest);
if (outcome.isSuccess()) {
std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
}
else {
/* Handle exceptions. */
std::cout << "AppendObject fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Carga multiparte
Si llama a la operación CompleteMultipartUpload para finalizar la tarea de carga multiparte de un objeto en un bucket con control de versiones habilitado, OSS genera un identificador de versión único para dicho objeto. Este identificador se devuelve como valor del encabezado x-oss-version-id en la respuesta.
A continuación se muestra cómo ejecutar una carga multiparte:
#include <alibabacloud/oss/OssClient.h>
#include <fstream>
int64_t getFileSize(const std::string& file)
{
std::fstream f(file, std::ios::in | std::ios::binary);
f.seekg(0, f.end);
int64_t size = f.tellg();
f.close();
return size;
}
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize the OSS account information. */
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
std::string Endpoint = "yourEndpoint";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
std::string Region = "yourRegion";
/* Specify the bucket name. Example: examplebucket. */
std::string BucketName = "examplebucket";
/* Specify the full path of the Object. The full path cannot contain the bucket name. Example: exampledir/exampleobject.txt. */
std::string ObjectName = "exampledir/exampleobject.txt";
/* Initialize network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
InitiateMultipartUploadRequest initUploadRequest(BucketName, ObjectName);
/* Initialize the multipart upload event. */
auto uploadIdResult = client.InitiateMultipartUpload(initUploadRequest);
auto uploadId = uploadIdResult.result().UploadId();
std::string fileToUpload = "yourLocalFilename";
int64_t partSize = 100 * 1024;
PartList partETagList;
auto fileSize = getFileSize(fileToUpload);
int partCount = static_cast<int>(fileSize / partSize);
/* Calculate the number of parts. */
if (fileSize % partSize != 0) {
partCount++;
}
/* Upload each part. */
for (int i = 1; i <= partCount; i++) {
auto skipBytes = partSize * (i - 1);
auto size = (partSize < fileSize - skipBytes) ? partSize : (fileSize - skipBytes);
std::shared_ptr<std::iostream> content = std::make_shared<std::fstream>(fileToUpload, std::ios::in|std::ios::binary);
content->seekg(skipBytes, std::ios::beg);
UploadPartRequest uploadPartRequest(BucketName, ObjectName, content);
uploadPartRequest.setContentLength(size);
uploadPartRequest.setUploadId(uploadId);
uploadPartRequest.setPartNumber(i);
auto uploadPartOutcome = client.UploadPart(uploadPartRequest);
if (uploadPartOutcome.isSuccess()) {
Part part(i, uploadPartOutcome.result().ETag());
partETagList.push_back(part);
}
else {
std::cout << "uploadPart fail" <<
",code:" << uploadPartOutcome.error().Code() <<
",message:" << uploadPartOutcome.error().Message() <<
",requestId:" << uploadPartOutcome.error().RequestId() << std::endl;
}
}
/* Complete the multipart upload. */
CompleteMultipartUploadRequest request(BucketName, ObjectName);
request.setUploadId(uploadId);
request.setPartList(partETagList);
auto outcome = client.CompleteMultipartUpload(request);
if (outcome.isSuccess()) {
std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
}
else {
/* Handle exceptions. */
std::cout << "CompleteMultipartUpload fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release network resources. */
ShutdownSdk();
return 0;
}Referencias
Para obtener más información sobre las cargas simples, consulte PutObject.
Para obtener más información sobre las cargas por anexión, consulte AppendObject.
Para obtener más información sobre las cargas multiparte, consulte CompleteMultipartUpload.